Making gold nanoparticles - a real breakthrough?

I found this scientific paper that showed how, using off-the-shelf cinnamon powder, one can generate gold nanoparticles from a gold salt without any expensive lab equipment or electrolysis. In my view, this might also work for producing silver nanoparticles, and if it does, it would enable the production of very high quality colloidal silver solutions without electricity, CS generators, or the expense of purchasing the solutions from vendors. Besides, colloidal gold can be helpful by itself!